Assig-nob to western electric



F. R. McMURRY.

TELEGRAPH SYSTEM.

APPLICATION FILED H8. 14, 1918.

1,324,838. Patented Dec 16,1919.

RECEIVING.

e srarns ragnnr FRED a. MCMURRY, or wEs'rwoon,- NEW JERSEY, assrenon r WESTERN ELEcrmo COMPANY, OENEW YORK, n. Y., A ooaroaarron or NEW YORK.

TELEGRAPH SYSTEM.

Patented Dec, 16, 1919.

Application filed February 14, 1918. Serial No. 217,137.

To, all whom it may concern:

'Be it known that I, FRED R. MGMURRY,

a citizen of the United States, residing at VVestwood, in the county of Bergen and State of New Jersey, have invented certain clear, concise, and exact description.

This invention relates to-telegraph systems, and particularly to printing telegraph systems.

One object of thisinvention is to provide a printing telegraph system with means for transmitting an auxiliary signal, whereby a receiving operator may at any time break in on the transmission of a message and operate a signaling device at the transmitting station.

In the operation of printing telegraph systems it is desirable that the' receiving operator be able to stop the transmission of a message and operate a signal at the transmitting station in case it is desired to have a portion of the message repeated. or for any other similar reason. If no provision is made for the receiving operator to'break in on the transmission of a message, it is necessary for the receiving operator to wait until 'the complete message has been transmitted,

and then signal back to'the transmitting op erator. Such a procedure is inconvenient and impractical inasmuch as it may be necessaryin many cases to retransmit the complete message.

In a printing telegraph system constructed in accordance with this invention a signaling relay which is controlled by the receiving operator or operators is provided at the transmitting station for operating a signaling device and for stopping the transmission of a message. The illustrated printing telegraph system embodies a transmitting station for transmitting impulses of the same strength and polarity over a line wire to 'a line relay at the, receiving station. The various signals formed by the impulses'are differentiated from each other by transmitting the impulses with various blank spaces or periods of no current 'therebetween. The system utilized for illustrating this invention employs a five unit code made 11p of permutations of current impulses and'intervals of no current. It is to be understood, however, that the invention is equally applicable to a system in which the various signals are selected by a greater or less number of impulse's and in- Enro tervals of no current. Potential is normally maintained on the main line. and, when the signal is to be transmitted, current is re-' are normally transmitted by the sending station, These impulses of opposite polarity will operate a polarized relay at the sending station, which is unaffected by the impulses normally transmitted over line Wires'for operating the receiving line relay. The polarized relay, when operated, opens the line wire to prevent'further transmission of a message and operates, a signaling device to call the sending operators attention thereto.

In the system illustrated in the drawing,

one sending and-receiving station are illustrated, but it is to be understood that the system may be provided with any number of stations and that each station may be provided with sending and receiving apparatus.

The single figure in the accompanying drawing is a diagrammatic view of a printing telegraph system constructed in accordance with this invention.

Referring to the drawing, a sending station 1 and a receiving station 2 are connected by a line wire 3 havlng grounded terminals. The sending station 1 1s provided with a suitable current-controlmeans 4', which selects the impulses which are to be transmitted from a battery 5 over the line conductor 3 to the receiving station, a sunflower switch 6 for transmitting the selected impulses to the line wire, a sending-start relay 7 for initiating the operation of the sending and receiving apparatus, and a start-magnet 8 which is controlled by the sending-start relay for initiating the operation of the sunflower switch 6. v

The current-control means 4 embodies a.

Y and 13 which are'selectively connected to a contact member 14. The current-control means 4 is also provided with a switch member 15 which is moved to engage a contact terminal 16 whenever the contact terminals 9 to 13 inclusive are operated selectively to engage the contact member 14. The switch member 15 and its associated contact terminal 16 serve for initiating the operation of the sending-start relay 7.

T he sendin -start relay 7 embodies an energizing coil T7, which is connected to a battery 18 by means of the switch member 15, and a holding coil 19, which is connected to a battery 20 by means of an associated arm-a;

ture 21. The relay 7 is also provided with an armature 22 which serves for completing a circuit from the battery 18 through the start magnet 8.

The sunflower switch 6 embodies a plurality of contact segments 24, 25, 26, 27 and 28 which are respectively connected to the contact terminals 9 to 13 inclusive and may also be connected to a contact ring 29 of the sunflower switch by means of a brush 30 mounted on a rotatable brush arm 31. A brush 32 is provided for connecting a contact segment 33 to a contact ring 47 in order tocomplete a circuit through the coil 19 of the sending-start relay 7 when the contact 1 member 15 is operated. The brush arm 31 is frictional-1y mounted on a constantly rotating shaft and is prevented from rotating by means of a latch 34 which is controlled by the start magnet 8.

A signaling relay 35 is provided at the sending station which is unafiected by-the impulses that are transmitted over the line wire 3 from the'battery 5, but which is operated by stronger impulses of an opposite polarity which are received from the receivmg station 2. A polarized armature 36 which is controlled by the relay 35 is adapted to complete a circuitfrom a battery 37 through a relay 38-when operated. The relay 38 is provided with an armature 39 for completing a circuit from a battery 40 through a signaling device 41, an armature 42 for establishing a locking circuit for the relay, and an armature 43 for opening the line circuit 3.

The receiving station 2 embodies a selecting mechanism 50 for selecting the character "to be printed, asunfiower switch 51 for distributing the received impulses to the selecting mechanism, and a rece1v1ng line relay 52 which is operated in accordance with the imulses received from the sending station.

he selectingmechanism 50 may be of any 1 suitable type and embodies a plurality of selecting magnets 53, 54, 55, 56 and 57 which are respectively connected to contact segments 58, 59, 60, 61 and 62 of the sunflower switch 51. The contact segments 58 to 62 in- '69 is provided with a lat-ch 7 0 for releasing the brush arm 65 in a manner similar to the l release of the brush arm 31by the start magnet 8 at the sending station. Two contact segments 71 and 72, which are bridged by the brush 64, are provided for completing a circuit through any suitable recording or printing mechanism, as, for example, a

printing magnet to record the selected character. The line relay 52 is provided with an armature 73 for connecting-a battery 74 to the contact ring 63 when in an operative position, and for connecting the battery 7-4 to the ring 66 when in a released position- The receiving station 2 is also provided with a switch member 75 which is adapted to connect a battery 76 to the line wire 3.v

The battery 76, as hereinbefore set forth, is adapted to transmit stronger impulses of an opposite polarity to those which are transmitted from the battery 5 at the sending station.

A line relay 45, at'the sending station, 6

may be utilized for operating a home recorder if 'so desired.

In describing the operation of the system cuit through sending-start relay may be traced from ground through the battery '18, coil 17, switch member 15 contact terminal 16, contact segments 33, brush. 32 and the contact ring 47 -to ground. The armature 22 of the relay 7 completes a circuit, for op- 1 crating the start magnet 8 and the armature it is assumed that the first character of the v minals 16in order to complete a circuit through the sending-start relay 7 The cir- 21 completes a holding circuit for the sending-start relay which may be traced from ground conductor through battery 20, arma ture 21, coil 19, contact segment 33, brush 32 and the contact ring 47 to ground. It should be noted, however, that the holding circuit for the start relay 7 is only maintained during the period that the brush '32 is bridging the contact segment 33 and the contact ring 47. Y

In the initial position of the sending sunflower switch 6, a circuit is completed from the battery 5 through the contact segment brush arm 31 is released by the latch 34:,

- the brush 30 is rotatedin a counterclockwise direction to break the circuit above 'men- 10. tioned from the battery 5 to the line wire 3 for releasing the,v line relay 52 for a purpose to. beset forth hereinafter. The brush 32 disengages the contact segment 33 in order 'to open the holding circuit of the sending-' start relay 7 and permit the release of the latch 34 of the start relay 8. It is essential to release the start magnet Sin order to pre-' vent more than one simultaneous rotation of the brush arm 31. The brush arm 31 in its mwntinued counterclockwise rotation successively connects the contact segments 28, 27,

26, and'2 l to the contact ring 29 which I is directly connected to the line wire 3. Accordingly, upon engagement of the brush 3O 25 withthe segments 28 and 24, impulses will be transmitted from the battery 5 over the line wire to .the receiving relay 52 and, intermediate the two impulses which are transmitted through the segments 28 and 24, three 80 periods of no current are interposed while the brush arm31 is rotated over the segments 27, 26 and 25.

Inasmuch as the armature 73 of the line relay 52 is released by the opening of the 35 line wire 3 when'the brush 30 disengages the contact segment 23, a circuit is completed from the ground conductor through the battery 74, armature 73, contact ring 66, contact segment 67, and'the start magnet 40 69 to the ground conductor. The start magnet 69 is thus energized and the latch 70 is operated to release the brush arm 65. The brush arm 65 rotates, in a counterclockwise direction and, when the brush 68 disengages contact'segment 67, the start magnet 69 is deenergized to release the latch 70 in order to stop the rotation of the brush arm 65 when one complete rotation has been effected. The two brush arnis31 and 65 of the sending andv the receiving sunflower switches are considered to be rotated sub-- 'stantially i-n synchronism with each other, so that when the contact segments 28 to 24 inclusive of the sending sunflower switch are connected to the line wire 3, the contact segments 62 to 58-inclusive of the receiving sunflower switch are successively connected by the brush 64stothe contact ring 63, which in turn is connected to the battery 74 by the armature 73 whenever the line relay 52 is energized. Thus, during the rotation of the brush arm 65, a circuit is completed from the battery 74 through the selecting magnets 57 and 53 to preparefa character for printing, inasmuch as the relay 52 is operated when the brush 64 bridges contact segments 71 and 72. v

In case the receiving operator-desires to communicate with the sending operator and prevent the further transmission of a message, the switch member 75 is operated to 'connect'the battery76 to theline wire 3.

A strong impulse of opposite polarity is thereupon transmitted over the line wire 3 that operates the signaling relay 35. The armature .36 of the signalingrelay; completes a circuit through the relay 38, and I the relay 38 in turn operates a'signaling device 41 by means of the armature 39 and breaks the line circuit by means of the armature 43. When the line circuit has been broken by the armature 43 it is impossible to transmit a message until the transmitting operator opens the-holding circuit 0 the rela 38 by means 'of a switch 46.

Modi cations in the system and arrangement and location ofparts may be made within the spirit and scope of this invention and such modifications are intended to be covered by the appended claims.

What is claimed is:

1. In a printing telegraph system, the combination with a sending apparatus, areceiving apparatus, and a hne wire for connectin the same, of a. line relay associated with't e receiving apparatus .for governing the operation thereof, a signal relay associated with the sending apparatus and responding only when impulses of a different character from those normally operating the line relay are transmited over the line wire, a second relay controlled by said signal re-".- lay and having a holding circuit, and a signal device controlled directly by said second re ay. 105

2. In a printing telegraph system, the combination with a sending station, a receiving station, a line wire for connecting sald stations, and a signaling device disposed at the sending station, of a line relay I o controlled by impulses recelved over the fline wire for governing the operation of the impulses transmitted over the line wire for 125.- governing the operation of the receiving apparatus, a signaling relay'operated only by impulses diflerent in character from the impulses normally transmitted over the line wire for operating the line relay, and means 13Q controlled by the signal relay for holding the line wire open and for operating said signaling device.

4. In a printing telegrabh system, the

combination with a sending station, a receiving station, a line wire for connecting '-said stations, and a signaling device, a siglay operated only by iinpulses of a difierent polarity from the lmpu-lses normally operating the line relay, and means controlled by the polarized relay for operating the signaling device through the instrumentality of said signaling relay and for holding the line Wire open.

In, Witness whereof, I hereunto subscribe my name this 29th day of December, A. D., 1917.

' F; R. MQMURRY. 

